My laboratory is also evaluating the utility of gene methylation in the early detection of upper GI cancer among subects in a high-risk region of China. This work is being conducted in a population-based screening cohort, the Cytology Sampling Study 2 (CSS2). The CSS2 was conducted to estimate the sensitivity of the newly designed esophageal cytology sampler for detecting squamous dysplasia and carcinoma (ESCC) in comparison with the standard balloon cytology sampling devise. Molecular markers are currently being evaluated in both cytology cells and serum to predict esophageal dysplasia/cancer to facilitate large-scale screening of high-risk populations. Gene methylation may be a good candidate marker for these studies.